Counting garter stitch rows

I had to rip out several rows and now am trying to count what I have completed. My instructions were to k 12 rows. I find it very difficult to see the stitches and am not sure what piece of the sitch to count for a row marker. Any suggestions?

For garter, you can count each ridge as two rows, or count each ridge and space between it as one row each.

When you have 6 ridges on each side, you’ve done 12 rows.